PRF/J: Molecular Genetics of Wing Coloration Polymorphism in Heliconius Butterflies: Isolation, Characterization and Phylogenetic Analysis of Linked Nuclear DNA Regions

新热带拟态蝴蝶(共38种)翼型变异的演化是研究遗传漂移和自然选择在地理小种形成中的作用的理想系统。多年来对这一系统的研究未能揭示出可能归因于令人震惊的不同异位形式的潜在机制。通过鉴定在回交后代中与翼型等位基因共分离的随机扩增多态性DNA分子遗传标记，将有可能鉴定和测序与一个广布物种的多个地理小种的模式改变等位基因连锁的核DNA片段。对不同小种之间每个模式相关标记的系统发育分析将与线粒体基因的种内关系的独立系统发育假说进行比较，以确定异地小种中相似的翅膀模式是通过选择随着时间的推移保持的，还是从不同的祖先繁殖而独立出现的。%的结果将加深我们对交替进化力量在拟态复合体产生中的作用的理解，并为赫利柯斯的基因组图谱研究提供初步的模板。本研究还将从分子水平阐明选择对表型的影响。识别在功能上参与模式形成的基因的可能性是令人兴奋的，因为已经假设负责翅膀模式的发育途径在所有蝴蝶(可能包括所有鳞翅目)中是同源的。如果这是真的，它将对整个分子发育生物学产生深远的影响。

The evolution of wing pattern variation in Neotropical mimetic Heliconius butterflies (altogether 38 species in the genus) is an ideal system for investigating the roles of genetic drift and natural selection in the formation of geographical races. Years of studying this system have failed to reveal underlying mechanisms to which a stunning diversity of distinct allopatric forms may be attributed. By identifying RAPD molecular genetic markers that co- segregate with wing-pattern alleles in backcrossed broods, it will be possible to identify and sequence nuclear DNA fragments linked to pattern-altering alleles from multiple geographical races of a widespread species (Heliconius erato). A phylogenetic analysis of each pattern-related marker among different H. erato races will be compared to an independent phylogenetic hypothesis of intraspecific relationships from a mitochondrial gene, to determine if similar wing patterns in allopatric races have been maintained over time by selection, or have arisen multiply and independently from separate ancestors. %%% Results will enhance our understanding of the roles of alternate evolutionary forces in the production of a mimicry complex and provide a preliminary template for genomic map studies in Heliconius. This study will also illuminate the effects of selection on phenotype at the molecular level. The possibility of identifying genes that are functionally involved in pattern formation is an exciting one, for it has been hypothesized that the developmental pathway responsible for wing patterns is homologous in all butterflies (and possibly all Lepidoptera). If this is true, it would have far reaching implications for molecular developmental biology in general.